The present invention relates to a protective tube for shielding against the environment, an auxiliary tool, a set or kit with a protective tube and an auxiliary tool, and an arrangement with a protective tube supply and an auxiliary tool.
Protective tubes are used in the most different fields to protect, for instance, electrical or pneumatic lines and tubes against outside influences. Such protective tubes are also used to bundle a plurality of cables or individual wires. To give such protective tubes, which are normally made from plastics, a high stability, particularly regarding external influences, and to make them flexible at the same time, these are configured as so-called corrugated tubes. The diameters of said tubes may vary greatly and may normally range from a few millimeters to some ten millimeters or more.
To lay lines in such protective tubes, these must be drawn in from one end. If lines are to be laid over large distances in such protective tubes, it gets more and more difficult to draw in the cables with an increasing length, so that it is often imperative to use draw-in aids that are first of all threaded into the protective tube to subsequently fasten the cables and lines to be drawn in at the end, so that these can then be pulled with the draw-in aid through the protective tube. If other cables are to be added in a protective tube in which cables have already been drawn in, such a draw-in operation gets more and more difficult even if a draw-in aid is used. This is equally true when cables have already been laid, i.e. in the area of a computer workstation, which are later to be collected within a protective tube. That is also why protective tubes are offered that are longitudinally slit, so that these protective tubes can be opened to insert the cables subsequently. Most of the time the edges of the protective tube along the slit are sharp-edged so that said sharp edges may cause injuries if the edges are opened with the mere hand. The edges are also under such a tension that it is difficult to open the tube along the longitudinal slit. A further problem presented by such slit protective tubes manifests itself in that, after the tube has been opened, the edges are not always exactly adjoining one another aligned in one plane; it may e.g. happen that the one longitudinal edge slides over the other longitudinal edge, so that the diameter of the tube is also reduced. Moreover, the appearance is also deteriorated, e.g. whenever such protective tubes are used in visible areas, for example, to bundle the cables of a personal computer at a workplace.
DE 20 2004 009 048 U1 describes a simple, axially slit corrugated tube made of plastics for accommodating cables, wires, metal lines, or the like, in the case of which the slit is made wavelike. This wavelike configuration of the slit is to make sure that the cables or wires in bends are held in a much better way in the corrugated tube.
A protective tube for cables or a protective casing for cables in the form of a long plastic tube is described in DE 200 13 481 U1. In this protective tube the areas of the free edges are superposed, so that the protective tube is closed in the area of the slit without leaving a free gap.
DE 10 2004 005 310 B4 describes a corrugated tube as a protective sheath for electrical cables in automotive vehicles. Said corrugated tube comprises a slit extending throughout its length, as well as closing means for closing the same. The closing means are hook-like projections at the one edge along the slit that engage into matching projections at the other edge of the slit in that they grip over the respective other projections or come to rest thereunder. To close the tube along the slit, the hooking of the projections constitutes a troublesome operation.
DE 696 22 048 T2 (translation of EP 0 883 922 B1) describes a slit corrugated tube in the case of which a tongue or tab is provided along the slit on a longitudinal edge, the tongue or tab moving under the edge of the other longitudinal edge of the corrugated tube, so that position and orientation of the two longitudinal edges relative to each other are fixed. This document also indicates a method for producing such a corrugated tube by extrusion by way of chain or sheet extruders.
Since, as has already been described above, it is difficult to open a slit protective tube to insert cables therein, DE 200 13 481 U1, which has already been indicated above, provides an auxiliary tool as a lead-in clamp. Said lead-in clamp comprises two shaped parts, each consisting of a clamp mount and a clamp body, which are held by a clamp spring such that a cable guide cylinder can be opened against the pressure of the clamp spring to insert cables into the cable guide cylinder, and is re-closed by the pressure of the clamp spring and also kept closed. Furthermore, a guide member, called housing head, is provided, which adjoins the clamp body, and a constriction line along which the two edges of the cable protection housing are spread is formed between the clamp body and the housing guide head at both sides; the housing guide head is here extending through the interior of the cable protection housing and serves as a guide member. Simultaneously with the displacement of said auxiliary tool along the slit, cables can be inserted into the interior of the cable protection housing via the cable guide cylinder. The cable protection housing can be closed again behind the lead-in clamp. It is difficult to handle this lead-in clamp insofar as an exact guidance is not guaranteed all the time, and it may happen that the lead-in clamp jumps out of the slit; this may particularly be the case when cables that are quite thick are to be inserted into the cable protection housing. Furthermore, this system poses the problem that the edges along the slit of the cable protection housing come to rest one on top of the other in the closed position thereof, whereby different diameters of the cable protection casing may arise that depend, inter alia, on the plastic material used, the age of the cable protection housing and the quantity of the inserted cables.